1. Field of the Invention
The present invention relates to an opening and closing mechanism of a door that openably and closably covers an opening of a casing, and an image forming apparatus that comprise the opening and closing mechanism.
2. Description of the Related Art
In conventional image-forming apparatuses, a photoconductor, as an image bearing member, is charged uniformly, and a latent image becomes formed on the photoconductor through selective exposure of the latter. The latent image on the photoconductor is developed by a developer, to become manifest in the form of a developer image that is thereafter transferred to a recording material.
Through application of heat and pressure to the transferred developer image, an image is recorded in that the developer image is fixed onto the recording material. The periphery of such an image-forming apparatus is conventionally covered by a casing, with an opening provided in part of the casing in order to replenish developer and perform maintenance of various process means. Preferably, such a casing opening is closed during everyday use, to secure safety and sound-proofing. Accordingly, the opening is ordinarily covered by a door that is supported on an apparatus body in such a manner that the door can be opened and closed (see Japanese Patent Application Publication No. 2005-327918).
FIGS. 14A, 14B are schematic diagrams illustrating the configuration of a casing of a conventional laser printer, as an example of such an image-forming apparatus. As illustrated in the figure, a dedicated opening 230 is provided, so as to enable replenishment of developer, in an apparatus body 202. At times other than during maintenance, the opening 230 is closed by a door 203 that is provided in the apparatus body 202. A pivot 250 that is formed protruding from both side end sections at one edge of the door 203 fits into a bearing portion (not shown) that is formed in the apparatus body. The door 203 is rotatably mounted thereby about the pivot 250. The door 203 allows keeping the opening 230 normally in a closed state, while during replenishment of developer, the opening 230 can be brought to an open state through rotation of the door 203.
As described above, a door opening and closing mechanism is conventionally resorted to wherein a hinge mechanism enables a rotation operation about a pivot that facilitates a smooth opening and closing operation.
However, a concern arises in that if such a hinge mechanism is used, the shape of the opening and closing door of the apparatus and the position of the hinge may be constrained in order to achieve the following configuration. This configuration is namely a configuration that precludes the occurrence of a large clearance between the door 203 and another casing exterior (exterior part 210) covering the apparatus body 202 upon closing of the opening 230, and that prevents the opening and closing operation of the door 203 from being hindered on account of interference between the door 203 and other constituent parts that are provided inside the apparatus body.
Demands concerning functionality at low cost and better design have been placed on image-forming apparatuses in recent years. To meet these demands, the added value of products has to be increased by making clearances between constituent parts as small as possible, while keeping costs down.